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+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code distributions
+ * retain the above copyright notice and this paragraph in its entirety, (2)
+ * distributions including binary code include the above copyright notice and
+ * this paragraph in its entirety in the documentation or other materials
+ * provided with the distribution, and (3) all advertising materials mentioning
+ * features or use of this software display the following acknowledgement:
+ * ``This product includes software developed by the University of California,
+ * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
+ * the University nor the names of its contributors may be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/* \summary: Address Resolution Protocol (ARP) printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "ethertype.h"
+#include "extract.h"
+
+
+/*
+ * Address Resolution Protocol.
+ *
+ * See RFC 826 for protocol description. ARP packets are variable
+ * in size; the arphdr structure defines the fixed-length portion.
+ * Protocol type values are the same as those for 10 Mb/s Ethernet.
+ * It is followed by the variable-sized fields ar_sha, arp_spa,
+ * arp_tha and arp_tpa in that order, according to the lengths
+ * specified. Field names used correspond to RFC 826.
+ */
+struct arp_pkthdr {
+ nd_uint16_t ar_hrd; /* format of hardware address */
+#define ARPHRD_ETHER 1 /* ethernet hardware format */
+#define ARPHRD_IEEE802 6 /* token-ring hardware format */
+#define ARPHRD_ARCNET 7 /* arcnet hardware format */
+#define ARPHRD_FRELAY 15 /* frame relay hardware format */
+#define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */
+#define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */
+#define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */
+#define ARPHRD_INFINIBAND 32 /* InfiniBand RFC 4391 */
+ nd_uint16_t ar_pro; /* format of protocol address */
+ nd_uint8_t ar_hln; /* length of hardware address */
+ nd_uint8_t ar_pln; /* length of protocol address */
+ nd_uint16_t ar_op; /* one of: */
+#define ARPOP_REQUEST 1 /* request to resolve address */
+#define ARPOP_REPLY 2 /* response to previous request */
+#define ARPOP_REVREQUEST 3 /* request protocol address given hardware */
+#define ARPOP_REVREPLY 4 /* response giving protocol address */
+#define ARPOP_INVREQUEST 8 /* request to identify peer */
+#define ARPOP_INVREPLY 9 /* response identifying peer */
+#define ARPOP_NAK 10 /* NAK - only valid for ATM ARP */
+
+/*
+ * The remaining fields are variable in size,
+ * according to the sizes above.
+ */
+#ifdef COMMENT_ONLY
+ nd_byte ar_sha[]; /* sender hardware address */
+ nd_byte ar_spa[]; /* sender protocol address */
+ nd_byte ar_tha[]; /* target hardware address */
+ nd_byte ar_tpa[]; /* target protocol address */
+#endif
+#define ar_sha(ap) (((const u_char *)((ap)+1))+ 0)
+#define ar_spa(ap) (((const u_char *)((ap)+1))+ GET_U_1((ap)->ar_hln))
+#define ar_tha(ap) (((const u_char *)((ap)+1))+ GET_U_1((ap)->ar_hln)+GET_U_1((ap)->ar_pln))
+#define ar_tpa(ap) (((const u_char *)((ap)+1))+2*GET_U_1((ap)->ar_hln)+GET_U_1((ap)->ar_pln))
+};
+
+#define ARP_HDRLEN 8
+
+#define HRD(ap) GET_BE_U_2((ap)->ar_hrd)
+#define HRD_LEN(ap) GET_U_1((ap)->ar_hln)
+#define PROTO_LEN(ap) GET_U_1((ap)->ar_pln)
+#define OP(ap) GET_BE_U_2((ap)->ar_op)
+#define PRO(ap) GET_BE_U_2((ap)->ar_pro)
+#define SHA(ap) (ar_sha(ap))
+#define SPA(ap) (ar_spa(ap))
+#define THA(ap) (ar_tha(ap))
+#define TPA(ap) (ar_tpa(ap))
+
+
+static const struct tok arpop_values[] = {
+ { ARPOP_REQUEST, "Request" },
+ { ARPOP_REPLY, "Reply" },
+ { ARPOP_REVREQUEST, "Reverse Request" },
+ { ARPOP_REVREPLY, "Reverse Reply" },
+ { ARPOP_INVREQUEST, "Inverse Request" },
+ { ARPOP_INVREPLY, "Inverse Reply" },
+ { ARPOP_NAK, "NACK Reply" },
+ { 0, NULL }
+};
+
+static const struct tok arphrd_values[] = {
+ { ARPHRD_ETHER, "Ethernet" },
+ { ARPHRD_IEEE802, "TokenRing" },
+ { ARPHRD_ARCNET, "ArcNet" },
+ { ARPHRD_FRELAY, "FrameRelay" },
+ { ARPHRD_STRIP, "Strip" },
+ { ARPHRD_IEEE1394, "IEEE 1394" },
+ { ARPHRD_ATM2225, "ATM" },
+ { ARPHRD_INFINIBAND, "InfiniBand" },
+ { 0, NULL }
+};
+
+/*
+ * ATM Address Resolution Protocol.
+ *
+ * See RFC 2225 for protocol description. ATMARP packets are similar
+ * to ARP packets, except that there are no length fields for the
+ * protocol address - instead, there are type/length fields for
+ * the ATM number and subaddress - and the hardware addresses consist
+ * of an ATM number and an ATM subaddress.
+ */
+struct atmarp_pkthdr {
+ nd_uint16_t aar_hrd; /* format of hardware address */
+ nd_uint16_t aar_pro; /* format of protocol address */
+ nd_uint8_t aar_shtl; /* length of source ATM number */
+ nd_uint8_t aar_sstl; /* length of source ATM subaddress */
+#define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */
+#define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */
+ nd_uint16_t aar_op; /* same as regular ARP */
+ nd_uint8_t aar_spln; /* length of source protocol address */
+ nd_uint8_t aar_thtl; /* length of target ATM number */
+ nd_uint8_t aar_tstl; /* length of target ATM subaddress */
+ nd_uint8_t aar_tpln; /* length of target protocol address */
+/*
+ * The remaining fields are variable in size,
+ * according to the sizes above.
+ */
+#ifdef COMMENT_ONLY
+ nd_byte aar_sha[]; /* source ATM number */
+ nd_byte aar_ssa[]; /* source ATM subaddress */
+ nd_byte aar_spa[]; /* sender protocol address */
+ nd_byte aar_tha[]; /* target ATM number */
+ nd_byte aar_tsa[]; /* target ATM subaddress */
+ nd_byte aar_tpa[]; /* target protocol address */
+#endif
+
+#define ATMHRD(ap) GET_BE_U_2((ap)->aar_hrd)
+#define ATMSHRD_LEN(ap) (GET_U_1((ap)->aar_shtl) & ATMARP_LEN_MASK)
+#define ATMSSLN(ap) (GET_U_1((ap)->aar_sstl) & ATMARP_LEN_MASK)
+#define ATMSPROTO_LEN(ap) GET_U_1((ap)->aar_spln)
+#define ATMOP(ap) GET_BE_U_2((ap)->aar_op)
+#define ATMPRO(ap) GET_BE_U_2((ap)->aar_pro)
+#define ATMTHRD_LEN(ap) (GET_U_1((ap)->aar_thtl) & ATMARP_LEN_MASK)
+#define ATMTSLN(ap) (GET_U_1((ap)->aar_tstl) & ATMARP_LEN_MASK)
+#define ATMTPROTO_LEN(ap) GET_U_1((ap)->aar_tpln)
+#define aar_sha(ap) ((const u_char *)((ap)+1))
+#define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap))
+#define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap))
+#define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap))
+#define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap))
+#define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap))
+};
+
+#define ATMSHA(ap) (aar_sha(ap))
+#define ATMSSA(ap) (aar_ssa(ap))
+#define ATMSPA(ap) (aar_spa(ap))
+#define ATMTHA(ap) (aar_tha(ap))
+#define ATMTSA(ap) (aar_tsa(ap))
+#define ATMTPA(ap) (aar_tpa(ap))
+
+static int
+isnonzero(netdissect_options *ndo, const u_char *a, size_t len)
+{
+ while (len > 0) {
+ if (GET_U_1(a) != 0)
+ return (1);
+ a++;
+ len--;
+ }
+ return (0);
+}
+
+static void
+tpaddr_print_ip(netdissect_options *ndo,
+ const struct arp_pkthdr *ap, u_short pro)
+{
+ if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
+ ND_PRINT("<wrong proto type>");
+ else if (PROTO_LEN(ap) != 4)
+ ND_PRINT("<wrong len>");
+ else
+ ND_PRINT("%s", GET_IPADDR_STRING(TPA(ap)));
+}
+
+static void
+spaddr_print_ip(netdissect_options *ndo,
+ const struct arp_pkthdr *ap, u_short pro)
+{
+ if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
+ ND_PRINT("<wrong proto type>");
+ else if (PROTO_LEN(ap) != 4)
+ ND_PRINT("<wrong len>");
+ else
+ ND_PRINT("%s", GET_IPADDR_STRING(SPA(ap)));
+}
+
+static void
+atmarp_addr_print(netdissect_options *ndo,
+ const u_char *ha, u_int ha_len, const u_char *srca,
+ u_int srca_len)
+{
+ if (ha_len == 0)
+ ND_PRINT("<No address>");
+ else {
+ ND_PRINT("%s", GET_LINKADDR_STRING(ha, LINKADDR_ATM, ha_len));
+ if (srca_len != 0)
+ ND_PRINT(",%s",
+ GET_LINKADDR_STRING(srca, LINKADDR_ATM, srca_len));
+ }
+}
+
+static void
+atmarp_tpaddr_print(netdissect_options *ndo,
+ const struct atmarp_pkthdr *ap, u_short pro)
+{
+ if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
+ ND_PRINT("<wrong proto type>");
+ else if (ATMTPROTO_LEN(ap) != 4)
+ ND_PRINT("<wrong tplen>");
+ else
+ ND_PRINT("%s", GET_IPADDR_STRING(ATMTPA(ap)));
+}
+
+static void
+atmarp_spaddr_print(netdissect_options *ndo,
+ const struct atmarp_pkthdr *ap, u_short pro)
+{
+ if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
+ ND_PRINT("<wrong proto type>");
+ else if (ATMSPROTO_LEN(ap) != 4)
+ ND_PRINT("<wrong splen>");
+ else
+ ND_PRINT("%s", GET_IPADDR_STRING(ATMSPA(ap)));
+}
+
+static void
+atmarp_print(netdissect_options *ndo,
+ const u_char *bp, u_int length, u_int caplen)
+{
+ const struct atmarp_pkthdr *ap;
+ u_short pro, hrd, op;
+
+ ap = (const struct atmarp_pkthdr *)bp;
+ ND_TCHECK_SIZE(ap);
+
+ hrd = ATMHRD(ap);
+ pro = ATMPRO(ap);
+ op = ATMOP(ap);
+
+ ND_TCHECK_LEN(ATMTPA(ap), ATMTPROTO_LEN(ap));
+
+ if (!ndo->ndo_eflag) {
+ ND_PRINT("ARP, ");
+ }
+
+ if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
+ ATMSPROTO_LEN(ap) != 4 ||
+ ATMTPROTO_LEN(ap) != 4 ||
+ ndo->ndo_vflag) {
+ ND_PRINT("%s, %s (len %u/%u)",
+ tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
+ tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
+ ATMSPROTO_LEN(ap),
+ ATMTPROTO_LEN(ap));
+
+ /* don't know about the address formats */
+ if (!ndo->ndo_vflag) {
+ goto out;
+ }
+ }
+
+ /* print operation */
+ ND_PRINT("%s%s ",
+ ndo->ndo_vflag ? ", " : "",
+ tok2str(arpop_values, "Unknown (%u)", op));
+
+ switch (op) {
+
+ case ARPOP_REQUEST:
+ ND_PRINT("who-has ");
+ atmarp_tpaddr_print(ndo, ap, pro);
+ if (ATMTHRD_LEN(ap) != 0) {
+ ND_PRINT(" (");
+ atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap),
+ ATMTSA(ap), ATMTSLN(ap));
+ ND_PRINT(")");
+ }
+ ND_PRINT(" tell ");
+ atmarp_spaddr_print(ndo, ap, pro);
+ break;
+
+ case ARPOP_REPLY:
+ atmarp_spaddr_print(ndo, ap, pro);
+ ND_PRINT(" is-at ");
+ atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
+ ATMSSLN(ap));
+ break;
+
+ case ARPOP_INVREQUEST:
+ ND_PRINT("who-is ");
+ atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap),
+ ATMTSLN(ap));
+ ND_PRINT(" tell ");
+ atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
+ ATMSSLN(ap));
+ break;
+
+ case ARPOP_INVREPLY:
+ atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
+ ATMSSLN(ap));
+ ND_PRINT("at ");
+ atmarp_spaddr_print(ndo, ap, pro);
+ break;
+
+ case ARPOP_NAK:
+ ND_PRINT("for ");
+ atmarp_spaddr_print(ndo, ap, pro);
+ break;
+
+ default:
+ ND_DEFAULTPRINT((const u_char *)ap, caplen);
+ return;
+ }
+
+ out:
+ ND_PRINT(", length %u", length);
+}
+
+void
+arp_print(netdissect_options *ndo,
+ const u_char *bp, u_int length, u_int caplen)
+{
+ const struct arp_pkthdr *ap;
+ u_short pro, hrd, op, linkaddr;
+
+ ndo->ndo_protocol = "arp";
+ ap = (const struct arp_pkthdr *)bp;
+ ND_TCHECK_SIZE(ap);
+
+ hrd = HRD(ap);
+ pro = PRO(ap);
+ op = OP(ap);
+
+
+ /* if its ATM then call the ATM ARP printer
+ for Frame-relay ARP most of the fields
+ are similar to Ethernet so overload the Ethernet Printer
+ and set the linkaddr type for GET_LINKADDR_STRING() accordingly */
+
+ switch(hrd) {
+ case ARPHRD_ATM2225:
+ atmarp_print(ndo, bp, length, caplen);
+ return;
+ case ARPHRD_FRELAY:
+ linkaddr = LINKADDR_FRELAY;
+ break;
+ default:
+ linkaddr = LINKADDR_ETHER;
+ break;
+ }
+
+ ND_TCHECK_LEN(TPA(ap), PROTO_LEN(ap));
+
+ if (!ndo->ndo_eflag) {
+ ND_PRINT("ARP, ");
+ }
+
+ /* print hardware type/len and proto type/len */
+ if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
+ PROTO_LEN(ap) != 4 ||
+ HRD_LEN(ap) == 0 ||
+ ndo->ndo_vflag) {
+ ND_PRINT("%s (len %u), %s (len %u)",
+ tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
+ HRD_LEN(ap),
+ tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
+ PROTO_LEN(ap));
+
+ /* don't know about the address formats */
+ if (!ndo->ndo_vflag) {
+ goto out;
+ }
+ }
+
+ /* print operation */
+ ND_PRINT("%s%s ",
+ ndo->ndo_vflag ? ", " : "",
+ tok2str(arpop_values, "Unknown (%u)", op));
+
+ switch (op) {
+
+ case ARPOP_REQUEST:
+ ND_PRINT("who-has ");
+ tpaddr_print_ip(ndo, ap, pro);
+ if (isnonzero(ndo, (const u_char *)THA(ap), HRD_LEN(ap)))
+ ND_PRINT(" (%s)",
+ GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap)));
+ ND_PRINT(" tell ");
+ spaddr_print_ip(ndo, ap, pro);
+ break;
+
+ case ARPOP_REPLY:
+ spaddr_print_ip(ndo, ap, pro);
+ ND_PRINT(" is-at %s",
+ GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap)));
+ break;
+
+ case ARPOP_REVREQUEST:
+ /*
+ * XXX - GET_LINKADDR_STRING() may return a pointer to
+ * a static buffer, so we only have one call to it per
+ * ND_PRINT() call.
+ *
+ * This should be done in a cleaner fashion.
+ */
+ ND_PRINT("who-is %s",
+ GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap)));
+ ND_PRINT(" tell %s",
+ GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap)));
+ break;
+
+ case ARPOP_REVREPLY:
+ ND_PRINT("%s at ",
+ GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap)));
+ tpaddr_print_ip(ndo, ap, pro);
+ break;
+
+ case ARPOP_INVREQUEST:
+ /*
+ * XXX - GET_LINKADDR_STRING() may return a pointer to
+ * a static buffer, so we only have one call to it per
+ * ND_PRINT() call.
+ *
+ * This should be done in a cleaner fashion.
+ */
+ ND_PRINT("who-is %s",
+ GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap)));
+ ND_PRINT(" tell %s",
+ GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap)));
+ break;
+
+ case ARPOP_INVREPLY:
+ ND_PRINT("%s at ",
+ GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap)));
+ spaddr_print_ip(ndo, ap, pro);
+ break;
+
+ default:
+ ND_DEFAULTPRINT((const u_char *)ap, caplen);
+ return;
+ }
+
+ out:
+ ND_PRINT(", length %u", length);
+}
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